A 'simpler' solution would be to simply offer a complete alternative to javascript in the browser. If they released a new, fixed version of javascript, it would take at least a few years for the other browsers to catch up, assuming they even do (IE won't).

They actually did work out how to 'fix' many of javascript's issues over 10 years ago with the Javascript 2 proposal, but it never happened. http://www.mozilla.org/js/language/js20-2000-07/index.html If they had simply added type annotations, for example, javascript would be an order of magnitude faster today, and pretty much every language out there could easily compile to javascript without losing any speed or features.